The aim of the study: to analyze the expression of IMP3 and podoplanin in histological slides of gastric adenocarcinoma using the method of indirect double immunofluorescence. Materials and methods: Paraffin blocks of tumor tissue of 26 patients with gastric adenocarcinoma who underwent total gastrectomy from 2014 to 2018 at University Hospital Split were collected from the archives of the Clinical Institute for Pathology, Forensic Medicine and Cytology (hereinafter the Institute). Demographic characteristics were collected from the institution's archives, and data on the deceased from the coroner's evidence. The research was conducted in the laboratory of the Department of Pathology of the Medical School and the Institute's immunohistochemistry laboratory. In the pre-analytical procedure, 4 µm slides were cut from paraffin blocks, deparaffinized, rehydrated and stained I) with hemalaun-eosin for histological analysis, II) immunohistochemically on the Ventana Ultrabenchmark machine to control the tested method and III) manually using the method of double indirect immunofluorescence. The staining results of the first two methods were analyzed under a light microscope. In the immunofluorescent staining procedure, after antigen ritrieval cooking in citrate buffer, a cocktail of monoclonal rabbit antibody to IMP3 and monoclonal mouse antibody to podoplanin was applied, and incubated for 1 hour in a dark and humid chamber. The slides were then washed in PBS and a cocktail of species-specific secondary antibodies labeled with different fluorescent dyes was applied and incubated for 1 h. After washing in PBS, DAPI stain was applied for 5 minutes, slides washed in PBS and covered with Immunomont and a coverslip. Microscopic analysis was performed on the Olympus fluorescence microscope using a camera and the Cell Sens program. Results: The presence of IMP3 as a granular red signal in the cytoplasm of some tumor cells and podoplanin as a finely granular green signal in the endothelium of lymphatic vessels was demonstrated.